Not sure, but that doesn't sound good. if you have power for the fog machine, try wrapping it in a heating pad, and putting it in some sort of box to hold the heat in, also if the box is insulated enough the heat from the element might be enough to keep the juice from freezing. Maybe an old cooler?

Anti Freeze is a no no!!! Bad for the lungs... If I were you I would Wrap where the fluid is with with electric heat tape..... then throw a blanket on the top of it... I would make sure blanket does not touch heating elements.... the only thing you need to worry about is keeping the fluid warm and not freezing and busting your lines..... They also make heat blankets..... that could work too, because you can control the heat......

i know that i am a little too late to but if you put bubble wrap on the out side of the machine and then wrap it with a heating pad or blanket this will definetly work. because i came across the same thing but i wasnt going to a parade lol. anyways it was in the middle of halloween and all of the juice i put in my fogger froze in like 30 mins so after halloween season left i started playing around with different materials so i came up with bubble wrap and a heating pads like 2 of them and i used duck tape too hold them on there. but how i tested this therory was is i knew a friend at a local store and i asked him and like the store managers if i could use the meat freezer and that like is 29 below -0 in there and i tested it for like 2 days like that and the fog juice never froze. but i hope this helps and i know it worked for me but here u go.